Superheater.



W. A. MOFFAT.

SUPERHEATER.

APPLICATION FILED MAY 19. 1914.

1, M431 1 Patented June 29, 1915.

2 SHEETS-SHEET I.

W. A. MOFFAT. SUPERHEATER. APPLICATION FILED MAY 19, 1914.

Patented June 29, 1915.

2 SHEETS-SHEET 2.

WALTER A. MOFFA'I', OF ERIE, PENNSYLVANIA.

sornanm'ma.

Specification bf Letters Patent.

Patented June 29, 1915.

Application filed May 19, 1314:. Serial No. 839,564.

To all whom it may concern:

Be it known that I, WALTER A. MOFFAT, a citizen of the United States, residing at Erie, in the county of Erie and State of Pennsylvania. have invented new and useful Improvements in Superheaters, of which the following is a specification.

The invention relates to an improved superheater designed for use with steam boilers, and adapted to provide for an effective superheating of the steam generated in such boiler.

One of the objects of present invention is the provision of a superheater so arranged and constructed that it may be utilized as a baffie for the products of combustion, whereby to more effectively heat the superheating tubes.

A further object is the provision of a superheater of simple construction, wherein the superheating tubes are mounted in a header in a manner to permit their convenient removal when desired for renewal or repair.

The invention in the preferred form of details will be described in the following specification, reference being had particularly to the accompanying drawings, in which Figure 1 is a view in elevation, partly in vertical section. illustrating the application of the improved superheater to a boiler. Fig. 2 is a vertical section on line 2-2 of Fig. 1. Fig. 3 is a section on line 33 of Fig. 1. Fig. 1 is a longitudinal section through one of the superheater tubes and header. Fig. 5 is a longitudinal section through the lower header. Fig. 6 is a longitudinal section through the upper header. Fig. 7 is a longitudinal section through one end of one of the superheater tubes.

In carrying out the present invention, I arrange within the boiler above the usual tubes 1 therein what I term an upper header 2, and below and in advance of said tubes I arrange a lower header 3. The headers are of approximately identical construction, each comprising an outer cylindrical casing 1 and an inner concentric casing 5,.both of tubular formation. The outer casing is closed at each end by a removable cap 6 through which at the inlet end of the header the inner casing extends, thereby closing the inner casing against outer casing at this end of the header. The inner casing at the opposite end of the header is closed within the header by a removable plug 7, and an annular band arranged within the outer casing supports the closed end of the inner casing at this point, said band 8 being formed with a series of openings 9 to establish communication between the outer casing and the cap, an outer pipe 10 leading from the cap. Therefore at the inlet end the outer casing is closed against the incoming steam, while at the outlet end the outer casing :is in open communication with the outlet pipe.

The superheater tubes, which project in spaced parallel relation from and at right angles to each header, are of identical construction, each including a tube 11, closed at the end remote from'the header by a removable .plug 12. At the end adjacent the header, the tubes have a conical end 13 hereinafter termed an integral connector, the portion of largest diameter forming the extreme terminal of the tube. from which the tube gradually decreases in diameter throughout the length of the connector, as clearly shown in Fig. 7. Each superheater tube is divided longitudinally to present two passages through the medium of the plate 14: having a width corresponding to the interior diameter of the tube 11, the plate being passed longitudinally of the tube and throughout the length thereof. The plate 14 divides "the tube 11 into channels 15 and 16. said plate adjacent the free or outer end of the tube. being formed with an opening 17 to establish communication between the channels at this point. At the header connected end of the tube, the plate 14 is bent laterally and formed to provide a lip 18 which closes said end of the channel 16,

the Wall of the 'tube adjacent such closed end being formed with an opening 19.

To secure the superhea'ter tube in the header, the outerand inner casings 4 and 5 are formed with a transverse opening, ex-

tending entirely through both casings, the

lines-defining the walls of said openings be? ing convergent and corresponding at their smaller or inner ends with the points of the connector 13 of the tube, the edges of the outer and inner casings at such inner end of the openings being threaded so that the superheater tube may be passed longitudinally through said opening 20 inthe header, and secured in place by the threaded connection, a plug 21 being arranged in each of the casings at what may be termed the entrance end of the opening. In place, as shown 1n Fig. 4, the superheater tube projects through the header at the right angles thereto with the chamber 15 in open communication with the interior of the casing 5, while the channel 16 isin open communication with the space between the inner and outer casings through the opening 19.

The superheater tube from the upper header extends slightly downwardly from said header and are then projected in parallelism with the tubes 1, the superheater tubes, as shown in Fig. 2, being arranged intermediate the upper tubes, so as to form therewith a baflle. The lower header is arched and the tubes therefrom are encircled by sections of refractory material, as fire brick 21, each section being formed with a central opening, so as to be inserted over the end of the tube and moved longitudinally thereon. form an arch. The rear ends of the superheater tubes of the lower header are supported from the lower tubes 11 by a support including a split sleeve like clip 22, adapted to be inserted over the adjacent lower tube and having a depending strip 23 formed with an opening to receive the rear end of the superheater tube.

A pipe 24 leads from the steam drum 25 to the inlet end of the upper header, a pipe 26 leading from the outlet end of said upper header to the inlet end of the lower header. The outlet end of the lower header communicates through a pipe 27 with the engine or other point of use.

A pipe 28 opens to the atmosphere and communicates with the inlet end of the lower header, the outlet end of said lower header being in communication through the pipe 29 with the inlet end of the upper header. The various pipes leading to the headers are valves so that they can be cut off at will, and by the additional pipes described, it is obvious that an air circulation may be maintained through the superheater inde'pend ently of any other portion of the apparatus.

In use, the steam admitted to the upper header is passed successively through the respective chambers of the Various superheating tubes and delivered to the lower header and passed again throughthe superheating tubes thereof and through the engine or other point of use, the course of travel of the steamhaving been pointed out in the previous description.

The adjacent bricks interfit to What is claimed is A 'with an opening adjacent one end, and a strip having a width corresponding to the diameter of the body and positioned longitudinally of the body to divide the same into distinct channels, the end of the strip being upturned within the body to close the end of one of the channels beyond the opening.

3. A superheater comprising a casing including inner and outer concentric bodies, said bodies being formed with transverse registering openings together forming a passage of conical formation, tube having a conical terminal corresponding to the minimum dimension of the conical passage, whereby the tube may be inserted or removed through said passage, said tube having threaded connection with the walls-of the conical passage at the reduced ends thereof, and plugs closing the openings in the respective bodies at the enlarged end of the passage.

&. A superheater for steam boilers including an upper header and a lower header, each of said headers comprising concentric casings, superheater tubes projecting from the respective headers and each formed to provide distinctive channels communicating respectively with the casings of the header, a steam supply pipe communicating with the inner-casing of the upper header, a steam outlet pipe establishing communication between the outer casing of the upper header and the inner casing of the lower header, a steam feed pipe leading from the outer casing of the lower header, an air pipe communicating with the inner casing of the lower header, and an air pipe establishing communication between the outer casing of the lower header and the inner casing of the upper header, whereby a circulation of air may be maintained throughout the superheater at will.

In testimony whereof I afiix my signature Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

WashingtomD. C. I 

